This is an example how to configure Apache as a Reverse Proxy with SSL and Gerrit:

Apache VHost configuration:

NameVirtualHost *:443
<VirtualHost *:443>
      ServerName hostname:443

      SSLEngine on
      SSLCertificateFile /etc/pki/tls/certs/localhost.crt
      SSLCertificateKeyFile /etc/pki/tls/private/localhost.key

      ProxyRequests Off
      ProxyVia Off
      ProxyPreserveHost On
      SSLProxyEngine On

      <Proxy *>
            Order deny,allow
            Allow from all

      ProxyPass /


Gerrit configuration (only the relevant parts):

        canonicalWebUrl = https://hostname/
        listenUrl = proxy-

The canonicalWebUrl stands for the URL under which you want to reach the Gerrit interface. The listenUrl have to be exactly the same as the URL in the ProxyPass directive of the Apache configuration. The prefix proxy-https means, that the SSL handling is done by the Apache and not by Gerrit.